As the desire for enhanced communication bandwidth escalates, transmission media are pressed to convey information at higher speeds while maintaining signal fidelity and avoiding crosstalk. For example, a single communication cable may be called upon to transmit multiple communication signals over respective electrical conductors concurrently. Such a communication cable may have two or more twisted pairs of insulated electrical conductors (“twisted pairs”), each twisted to a different twist length or “lay length.” The twisted pairs may be imparted with different lay lengths in order to control interference associated with signal energy coupling between or among the pairs.
For a specific length of cable, a pair that is more tightly twisted has a longer signal path length than a pair that is less tightly twisted. Accordingly, signals traveling on different twisted pairs can take different amounts of time to traverse a cable. Such pair-to-pair variation in propagation delay, known as “skew,” can negatively impact cable performance. For example, cable purchasers may specify a maximum level of skew that is acceptable. Additionally, a pair that is more tightly twisted typically has a greater level of insertion loss or attenuation over a fixed cable length than a pair twisted more loosely.
One conventional proposal for addressing attenuation differences among twisted pairs within a cable involves varying insulation thickness among pairs according to pair twist. However, this approach to addressing variations in pair-to-pair attenuation often creates issues with inequality of pair-to-pair impedance and propagation speed. Such pair-to-pair imbalance can lead to cable-to-component mismatches and return loss problems, as well as incompatibilities with components of a communication system connected to the cable.
Accordingly, need exists for a technology that can enhance signal performance of a cable that comprises twisted pairs, including but not limited to improving pair balance, insertion loss, skew, attenuation, and/or crosstalk. A capability addressing such need or some other related deficiency in the art would elevate bandwidth that a communication cable can carry reliably.